1. Field of the Invention
The present invention relates to cultivating apparatus for movement below the surface of the ground for lifting plants for harvesting and for separating undesired grasses and weeds from the earth adjacent desirable crop materials. More particularly, the present invention relates to cultivator apparatus for digging peanut plants from the ground for harvesting, the apparatus including an improved cultivator blade for passage through the ground and for lifting the plants and plant roots for removal from the ground, in which the blade is self-sharpening for improved efficiency and has a ].lower drag to permit the cultivator blade to be more easily passed through the ground at a lower power input.
2. Description of the Related Art
Peanuts are harvested by digging the peanut plants from the ground and then separating the peanuts from the vines. Examples of cultivators for harvesting peanuts, and in which cultivator blades are provided in the form of a swept-back, generally triangular, sharp-edged plate are disclosed in U.S. Pat. No. 1,193,112, which issued Aug. 1, 1916, to J. H. Brodie, and in U.S. Pat. No. 2,167,044, which issued Jul. 25, 1939, to A. E. Henderson. Each of those patents discloses a unitary blade structure having two angularly arranged cutting edge surfaces for passage through the ground, for elevating the peanut plants, and for severing the roots of the plants from the ground. However, each of the disclosed blade structures has long body portions that extend in the direction of movement of the blade, and that are inclined relative to the direction of movement of the blade, which thereby increase the drag forces acting on the blade. Additionally, blades having leading edges that are so configured quickly become dull and must be removed for sharpening.
Another form of cultivator blade is shown in U.S. Pat. No. 2,345,702, which issued Apr. 4, 1944, to C. S. Noble. That patent discloses an elongated blade that extends across the path of travel of the cultivating apparatus, the blade being arc-shaped in cross section and having sharpened leading and trailing edges to permit the blade to be reversed when one of the edges has become dull. However, that cultivator blade structure also results in high frictional drag, thereby requiring more power for its operation. Additionally, the configuration and orientation of the blade edge relative to the direction of movement of the blade causes the blade edge to quickly become dull, thereby requiring early reversal of the blade, or sharpening of the blade if it had previously been reversed.
It is an object of the present invention to provide an improved cultivator blade structure that results in reduced drag forces acting on the blade and that thereby permits operation of the blade at a lower power input.
It is another object of the present invention to provide a cultivator blade that is capable of self sharpening when in use, to minimize the frequency of blade removal for sharpening.